Breakdancing has become a global phenomenon since it first emerged in the 1970s, even making its debut as an official event at this year's Summer Olympics. But hardcore breakers are prone to injury (sprains, strains, tendonitis), including a bizarre condition known as "headspin hole" or "breakdance bulge"—a protruding lump on the scalp caused by repeatedly performing the power move known as a headspin.